The invention disclosed herein pertains to a multiple position rotary switch.
Rotary switches are used in many applications for switching current values of 1mA to 25 amperes. Rotary switches of the indicated ratings are frequently used as control and function selectors in major domestic appliances such as dish and clothes washing machines and clothes dryers. The environment in these machines is usually wet, humid and soapy and is, therefore, hostile to electrical devices such as switches, connectors, and so forth. In the case of a rotary switch in such appliance, it is highly desirable for it to be sealed against entry of moisture or other contaminants which might cause a short circuit and/or corrosion that could disable the switch and the entire machine.
Preexisting rotary switches have weaknesses and difficulties which were not satisfactorily resolved before the new switch disclosed herein was made. One difficulty in preexisting rotary switches is that they often have backlash or freeplay which gives the user a poor feel as if there is elasticity in the parts when the switch is indexed by turning the operating shaft. A corollary to this is that the shaft feels unstable and, often is actually unstable, when the switch is being indexed rotationally from one position to another. Another difficulty has been to properly seal the switch against entry of contaminants along the switch operating shaft and where the lead wires enter and exit the switch. If the lead wires are not properly sealed and anchored, besides allowing entry of contaminants, physical forces on the lead wires externally of the switch housing can distort or dislocate the contacts inside of the housing, thereby causing the switch to operate erratically or fail completely.